My-humanity icon theme uses the new Nautilus icon for the folder icons as you can see in the screenshot below:

These aren't the official folder icons that will be available in Ubuntu 13.04 - they are custom icons built on top of the Nautilus icons we've seen a few days ago.

Besides the new folder Ubuntu Software Center and Software Updater icons, My-humanity comes with some other custom icons, so it's not identical to the Humanity icon theme available by default in Ubuntu. And it's pretty interesting!

To use My-humanity, extract the downloaded archive, copy the "my-humanity" folder in the ~/.icons folder (".icons" is a hidden folder in your home directory - if it doesn't exist, create it) and then use a tool like GNOME Tweak Tool, Ubuntu Tweak or Unsettings to change the icon theme to My-humanity.